u.stenzel at web.de
Mon Aug 14 08:22:55 EDT 2006
Bulat Ziganshin wrote:
> type classes is universal answer to almost any question ;)
Argh! Every complex problem has a simple and wrong answer, huh? At
some point you should stop generalizing, because doing everything
equally bad is the same as doing nothing right (but requires more work).
> data B = F | T deriving Boolean
toBool :: Silliness -> Bool
equivalent to isSilly or to isSensible? See, the gain in readability
is... uhm... questionable.
> class Enum a => Boolean a where
> fromBool :: Bool -> a
> toBool :: a -> Bool
> fromBool = fromEnum.toEnum
> toBool = fromEnum.toEnum
fromBool :: Enum b => Bool -> b
fromBool = fromEnum.toEnum
toBool :: Enum b => b -> Bool
toBool = fromEnum.toEnum
is a lot simpler and exactly as useful (read: not at all).
PS: No, I don't think 'perhaps' is all that useful. It lacks obvious
semantics and is easily defined should you need it, in which case
you also know how it should behave.
I loathe people who keep dogs. They are cowards who haven't got the
guts to bite people themselves.
-- August Strindberg
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